This invention relates to a method and apparatus for braking the rotating gears within a torque amplifier.
Many present farm tractors include a torque amplifier assembly which is located between the main engine clutch and the transmission of the tractor. The torque amplifier permits the operator to engage a torque amplifier gear when a desired increase in torque is required. The increase in torque can be accomplished with the torque amplifier without disengaging the clutch or shifting the gears in the transmission.
The torque amplifier assembly includes a first shaft which is coupled to the engine output shaft by means of the clutch. The first shaft includes a torque amplifier gear and a direct drive gear thereon. These gears interlock with complementary gears on a second shaft which in turn is drivingly connected to the transmission of the vehicle.
In normal operation of the torque amplifier, only one of the direct drive or torque amplifier gears is engaged at any given time. The hydraulic circuitry on present devices does not permit simultaneous engagement of the direct drive gear and the torque amplifier gear.
A problem is encountered with the present torque amplifier assemblies whenever the operator leaves the engine running with the clutch engaged and with the transmission in neutral. This would be the typical condition should the operator decide to dismount from the vehicle while leaving the engine running.
When the operator again mounts the vehicle and prepares to move forward again with the vehicle, he depresses the clutch and tries to shift the transmission into a driving gear. However, when he depresses the clutch, the amplifier gear and the direct drive gear continue rotating in a free wheeling action by virtue of their inertia. This prevents the operator from engaging the gears of the transmission without grinding the gears. Accordingly, the operator must wait for the rotation of the torque amplifier to stop before he can shift gears.
Present devices have placed mechanical brakes in mechanical engagement with the torque amplifier gear or direct drive gear to permit the operator to stop the rotation so that the gears in the transmission may be shifted. These present devices are cumbersome, usually require adjustment, and are inefficient.